The present invention relates to the field of electrical connectors and more particularly to an electrical jumper assembly for connecting electrical or electronic circuits.
Various methods exist for connecting separate electrical circuitry residing on rigid printed circuit boards, or within flexible printed circuits. A common technique referred to as point-to-point wiring uses conventional round wire to make the connections. However, this technique results in two major disadvantages. First, point-to-point wiring has high installation costs when there are multiple connections within a confined area. Second, there is a tendency for the round wire to break at the termination point after repeated flexing.
Electrical jumpers are designed to address these problems. Typically, the electrical jumpers include a flexible cable having a set of flexible conductors which are maintained in insulated and spaced relationship from each other. The intermediate portions of the conductors are typically flat for flexibility and are encapsulated in an insulating material. The flat portions of the conductors serve to distribute the flexing stress over the length of the jumpers. Thus, the electrical jumpers can withstand more repeated flexing stress than conventional round wire before breakage occurs. The conductor ends, commonly known as terminal pins, extend beyond the insulating material for connection into printed circuit boards or other electrical components. The fixed spacing between terminal pins permits easy insertion into printed circuit board hole patterns. Lower installation costs can be realized, since the multiple terminal pins of the electrical jumpers can be inserted into the female connectors as a single unit.
One type of electrical jumper is disclosed in U.S. Pat. No. 3,601,755 to Shiells. The electrical jumper includes a plurality of round wires whose intermediate portion is flattened by a pressure roller. The flattened portion of the wires are sandwiched between two sheets of plastic in a laminated structure with the planes of the flattened portions being coplanar. The round ends of the wire extend beyond the insulating material and remain in their original condition for use as terminal pins. Thus, the terminal pins and the intermediate portion of the conductors connecting the pins consist of the same type of material. This results in a compromise as to the rigidity of the pins and the flexibility of the conductors. Consequently, the pins may be too soft and easily bent out of position during insertion into the connector holes, while the conductors may be too hard and lack adequate flexibility.
Another technique for manufacturing electrical jumpers includes the step of etching away the intermediate portion of the conductor to form the desired flat shape. The etching process removes less of the conductor ends to achieve the desired thicker and therefore more rigid terminal pins. In either approach, the terminal pins are an integral extension of the conductors, thereby compromising the rigidity of the pins and the flexibility of the intermediate portion of the conductors.
It is a purpose of the present invention to provide a low cost electrical jumper assembly which does not compromise the rigidity of the terminal pins or the flexibility of the intermediate portion of the conductors connecting such pins.